(a) Field of the Invention
The present invention relates to a method for driving an electrophoretic display. More particularly, the present invention relates to a method for driving an electrophoretic display to provide the display of uniform images in each pixel in the electrophoretic display.
(b) Description of the Related Art
Recently, flat panel displays including an electrophoretic display (EPD) and a liquid crystal display (LCD) have been developed as substitutes for a cathode ray tube (CRT) display.
The electrophoretic display includes a thin film transistor array panel having a plurality of pixel electrodes, a common electrode panel having a common electrode, and an electrophoretic layer disposed between the two panels. The electrophoretic layer includes an electrophoretic member having a plurality of micro capsules and a maintaining resin for maintaining the electrophoretic member to the two panels. Each micro capsule includes electrophoretic particles that have positive or negative charges and move between the pixel electrodes and the common electrode, and a dielectric fluid in which the electrophoretic particles are dispersed.
In the driving process of the electrophoretic display, a common voltage as a reference voltage is applied to the common electrode and data voltages that are larger or smaller than the common voltage are applied to the pixel electrodes such that the electrophoretic particles disposed in each pixel are applied with the driving voltages of positive or negative charge corresponding to the differences between the common voltage and the data voltages. When applying the driving voltages, the electrophoretic particles that have positive or negative charges move between the pixel electrodes and the common electrode. The movements of the electrophoretic particles are finished when the desired images are displayed in the corresponding pixels, and then the corresponding pixels do not receive additional driving voltages until requirement of movement of the electrophoretic particles to display different images.
However, since the degree of movement of the electrophoretic particles is controlled by the application times of the driving voltages, the application times of the driving voltages are different for each pixel so as to display various images in each pixel. Accordingly, when the driving voltage is applied to a predetermined pixel but the driving voltage is not applied to a neighboring different pixel with reference to an arbitrary time, the electrophoretic particles disposed on the boundary of the two pixels receive the influence of the driving voltage applied to the predetermined pixel such that the electrophoretic particles disposed on the boundary move like the electrophoretic particles disposed in the predetermined pixel. Accordingly, the size of the image displayed in the predetermined pixel is increased compared with the neighboring different pixel. Accordingly, the entire display size between neighboring pixels becomes non-uniform.
Further, if the image display voltages are repeatedly applied to the electrophoretic particles to display images of various grays with time, arbitrary charges are stimulated in the two electrodes such that afterimages may be generated, thereby deteriorating display performance.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.